How Do Workplaces Demonstrate ALARP?

What is ALARP?

ALARP is a concept we are often tasked with explaining or proving for clients, but how can you demonstrate ALARP, and what is it?

In simple terms ALARP – or As Low As Reasonably Practicable is a technical term.  It says that you should do as much as you can to reduce a risk, as long as it is cost effective when considering the benefits that it brings. For a much longer explanation, check out the Health and Safety Executive’s resources on ALARP.

For us to “Demonstrate ALARP” we need to prove that there is nothing more cost effectively that could be done to reduce the risk further.  But in a world of countless design possibilities, where do we draw the line?

When we carry out HAZOP studies we leave our clients with one main task following completion of their actions: for anything that remains in the ALARP region of the risk matrix, ensure that risks can be shown to be ALARP.

ALARP Demonstration Options

Here is a handy guide as to the possible ways to demonstrate ALARP:

• Set up a tracking tool for all your ALARP demonstration cases, this should include:
  • Each ALARP demonstration case, and a cross reference to the hazard study this has come from
  • Improvement options considered
  • Reasons for exclusion of any improvements (e.g. practicalities, extreme cost, additional hazards introduced)
  • Costs and benefits considered for each measure, if it continues to be included as an option

Next up is the brainstorming part of the process.

• Are there any other obvious design options that could be employed, or improvements?
  • This may require some research, or discussing with your network in industry to see what else could be done to reduce risk.  A friendly process safety consultant may also be able to offer suggestions
  • For anything identified, if these are practical for your process – cost these improvements.
  • Improvements could be protective measures (pre event) OR mitigative measures (post event).
  • Improvements could be design features, additional instrumentation, post event protection systems – it really depends on the situation being assessed.

• What is relevant good practice (RGP) for this type of process, has this been followed?
  • For example, if it is an overpressure scenario, is there pressure relief included?
  • If RGP has not been included, then it should be included in a new design regardless of cost.
  • If this is review of previous design, RGP may have changed, implementation of RGP design measures should be costed.

Finally, for anything that is considered credible as an improvement and  you have developed a cost for, a cost benefit analysis might be required.

Cost Benefit Analysis

• Carry out a Cost vs. Benefit analysis, in line with typical industry guidance.
• There are many examples of Cost vs. Benefit methods, the one OTECSA use comes from recognised HSEx and industry guidance.
• The Cost vs. Benefit Analysis (CBA) involves several factors:
  • The risk of the event before the improvements
  • The risk of the event after the improvements – giving us a risk reduction
  • The “benefit” of the event – typically for safety this would be the reduced likelihood of an injury or fatality.  The HSEx put values on various injury levels, which are used in these calculations
  • A gross disproportion factor – this accounts for the fact we will be willing to spend more to stop a more serious event.  The HSEx provide guidance on typical gross disproportion factors.
  • The expected lifetime of the plant
  • The cost of the measures, in both CAPEX and OPEX costs
• The calculations then determine if the cost of the improvement you have identified is worthy of the risk reduction (the benefit), when considering the gross disproportion factor.
• If the benefits outweigh the costs, then the measures should be adopted.  If not, they are not justified on an ALARP basis.

So What Now?

With the conclusions of the cost benefit analysis, the assessor can then document which measures are deemed to be required to demonstrate ALARP.  Clearly documenting this process and calculations allows for future additional options to be considered, or decisions to be discussed.

With this handy guide, and access to the right references you too can navigate the world of ALARP demonstration.

We are often involved in assisting clients demonstrate ALARP for new projects or existing plant improvements.  If you would like to know more about any of the topics in this article, please get in touch.